Interplay between Plasmon Luminescence and Vibrationally Resolved Molecular Luminescence Induced by Scanning Tunneling Microscopy

TL;DR

This paper investigates how exciton-plasmon coupling affects molecular and surface plasmon luminescence, revealing the roles of molecular vibrational modes and re-absorption in shaping the spectra, consistent with recent experimental observations.

Contribution

It introduces a nonequilibrium Green's function approach to analyze exciton-plasmon interactions, highlighting the impact of molecular vibrational modes and re-absorption on luminescence spectra.

Findings

Molecular vibrational modes cause dip and peak structures in spectra.

Re-absorption by surface plasmons significantly influences spectral profiles.

Theoretical results align with recent experimental observations.

Abstract

Effects of coupling between a molecular exciton and a surface plasmon (exciton-plasmon coupling) on the luminescence properties of the molecule and the surface plasmons are investigated using the nonequilibrium Green's function method. Molecular absorption and enhancement by molecular electronic and vibrational modes (molecular modes) lead to dip and peak structures in the luminescence spectra of the surface plasmons. These structures will correspond to the peak and dip structures observed in a recent experiment. We found that in addition to the molecular dynamics, the re-absorption by the surface plasmons plays important roles in determining the luminescence spectral profiles.